Conventional fire hydrants offer access to a municipal water supply in a manner in which operatives with ill intent may appreciate. Briefly, conventional fire hydrants include at least one nozzle for coupling to a fire hose. The nozzle is closed off by a threaded cap when the hydrant is not in use. The hydrant also includes a hydrant valve which controls flow of water from the water supply to and through the hydrant, through the nozzle, and into the fire hose.
Conventionally, the barrel of the hydrant between the nozzle and the hydrant valve, which is in the lower portion of the hydrant, accommodates several gallons of fluid. Accordingly, it is possible to unscrew a nozzle cap, introduce gallons of toxin, reattach the nozzle cap and open the hydrant valve to allow the toxins to communicate with and flow by gravity and perhaps at least to some extent by Bernoulli's principle, into the municipal water supply, since when the nozzle cap is attached, water pressure from the water supply would not force the toxins back out of the hydrant.